Shell-encapsulated packets have many advantages including the ease of use and handling. For example, the exterior shell or capsule can prevent the consumers from touching the potentially harmful but functional necessary ingredients during the use of the product. However, there are also some challenges for providing shell-encapsulated consumer packets.
One such challenge is high temperature stability of the shell or capsule. Unlike pharmaceutical or biological agents, consumer products for household or personal usage are typically transported or even stored without robust air-conditioning, thus the shell or capsule would be exposed to relatively high temperature for a considerable duration before reaching to the retail market. It is difficult for conventional shells or capsules to stand such a rough condition, e.g., they are likely to become sticky or melt during transportation and storage.
Another challenge is the low temperature dissolution of the shell or capsule in water or neutral aqueous medium. Since the functional ingredients for the intended use are encapsulated in the shell or capsule, it is necessary to release the ingredients from the exterior shell or capsule for the final use. This releasing process is typically accomplished by dissolving the shell or capsule in water. Given the safety concern and energy-saving consideration, it is particularly desirable to use cold water around neutral pH, such as cold tap water. Many of the consumer products are used with appliances having automated cycle, such as the washing cycle of dishwasher or washer for cleaning laundry. It is difficult for conventional shells or capsules to dissolve in cold water around neutral pH, e.g., they may not dissolve fast enough to substantially or completely release the fill composition for its intended use, and thereby present a contamination problem, such as, for example, create a mess to clothes going to a dryer.
Since the preparation of the shell-encapsulated consumer product packet usually involves additional manufacture or assembly process compared to the ready-to-use liquid or solid products, another challenge is to make the consumer product packets quickly and economically.
The shell-encapsulated consumer product packets have wide use in general and are particularly suitable for having concentrated composition encapsulated in shell. However, it is difficult for conventional concentrated composition to be compatible with a shell for consumer products.